"tech - Thanks for that, the hp isn't much higher than the LS2, maybe it would be a better idea going with an LS2 (or similar), then I could sort out some kind of blower for it too."

You'll have to change the pistons to lower the compression ratio to about 8:1 in order to run a blower.

Using AFR heads, you could build a naturally aspirated 383 that would make more hp and torque than the Viper for half the money.